License Server: Clients fail to obtain license after server hostname or IP change

Description
After changing the license server machine’s hostname and/or IP address (for example due to IT migration or network reconfiguration), client applications can no longer obtain licenses. Users may see “Cannot connect to license server” or “License not found” messages, even though the license service is running on the server and worked previously.

Solution

1. Verify the license server is running
   • On the server machine, check that the License Server service is started and the license file is valid (correct host ID, not expired).
   • Confirm that the service listens on the expected TCP port (default per your deployment).
2. Update client configuration
   • On each client machine, either run Register.exe and click the License Server button at the bottom, or open the acdnmon.ini file from the installation folder.
   • Replace the old hostname or IP address with the new license server hostname or IP, then click OK or save the updated acdnmon.ini file.
   • Make sure the port number matches the license server configuration.
3. Check DNS and network connectivity
   • From a client machine, ping the new server hostname and verify it points to the correct IP.
   • If hostname resolution is unreliable, test using the IP address directly in the client configuration.
   • Confirm that no local firewall on client or server blocks the license port.
4. Restart services and retest
   • Restart the license server service after any configuration change.
   • Close and reopen the client application, then attempt license checkout again.